Support and tensioning apparatus for fourdrinier wire

ABSTRACT

IN THE FOURDRINIER SECTION OF A PAPER MAKING MACHINE, A SUPPORT MEMBER IS PROVIDED BENEATH THE FORMING WIRE. THE SUPPORT MEMBER HAS A FLAT SURFACE EXTENDING ACROSS THE WIRE AND SUBSTANTIALLY PARALLEL TO ITS TRAVEL AND SLIDINGLY SUPPORTING THE TRAVELLING WIRE A DISTANCE IN THE DIRECTION OF WIRE TRAVEL.

19, r, g 5 DE NOYER swam AND TENSIONING APPARATUS FOR FOURDRINIER WIRE Filed Jan. 19, 1967 7 "K '5 00 fl k- -l N VliN'l UR.

Dana/a A9. 0e Myer United States Patent 3,556,937 SUPPORT AND TENSIONING APPARATUS FOR FOURDRINIER WIRE Donald B. De Noyer, 37 Valley Road,

Beloit, Wis. 53511 Filed Jan. 19, 1967, Ser. No. 610,162 Int. Cl. D21f J/36 US. or. 162-273 8 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention The present invention relates to improvements in papermaking machines and more particularly to an improved Fourdrinier section and structure for supporting the travelling Fourdrinier wire. 7

Description of the prior art The looped Fourdrinier wire in a paper machine travels in a web forming run and a return run In a conventional construction the return run consists of a series of return rolls with tensioning rolls forming a zigzag path for the wire to return it from the couch roll back to the breast roll to begin its web forming run. Certain of the return rolls and tensioning rolls engage the inner surface of the wire and others engage the outer surface so as to be able to lengthen the effective path of the travel of the Wire and increase its tension. This structure has disadvantages which are increased as both the width and speed of paper machines are increased to increase machine capacity.

Paper machine Fourdrinier wires are generally made of a fine mesh wire screen of special formula bronze and some wires currently have been made of plastic. The Fourdrinier wire has a limited operating life and must be replaced periodically by shutdown of the machine and removal of the worn wire replacing it with a new wire. Since this replacement requires shutdown of the entire machine and necessary loss of production time any increase in operating life of the wire results in yearly savings of a substantial amount.

Wear and eventual breakage of the wire is due to frictional engagement with surfaces and to the necessity of the wire bending as it passes over a roll surface' The bending in the wire occurs with each return roll that it engages and in the return travel the wire must flex back and forth and be bent over the curvature of each of the return rolls. The bending also causes undesirable ridging in the wire. Also, ridging in the wire may result from poor fitting doctors, the eflects of which would permit the return fiber and water to rim the return rolls and ridge the wire as the fiber and water pass between the wire and the driving power necessary for the wire.

3,556,937 Patented Jan. 19, 1971 SUMMARY BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages will become more apparent with the teaching of the principles of the present invention in connection with the disclosure of the preferred embodiments thereof in the specification, claims and drawings, in which:

FIG. 1 is a schematic elevational view of a Fourdrinier section of a paper making machine illustrating the principles of the present invention;

FIG. 2 is another schematic elevational view showing a further arrangement;

FIG. 3 is a detailed side view of a wire support which is constructed in accordance with the principles of this invention; and

FIG. 4 shows an adjustable support member which may be used to support the Wire support of FIG. 3 to eliminat bowing of the wire support.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in FIG. 1, the closed looped travelling Fourdrinier wire F is arranged to have a horizontal forming run 1 and return run r. The web w of paper is formed on the upper surface of the forming run 1 with the stock being deposited thereon from a headbox 12.

The Wire is supported in its forming run 1 between a breast roll 10 and a couch roll 11 and dewatering devices such as table rolls 17 and suction boxes 18 are positioned beneath the wire along the forming run 1.

The wire travels downwardly at the end of its forming run over a first turning return roll 13 and at the end of the return run r passes over a turning return roll 14 up to the breast roll 10.

Along the return run are positioned a tensioning or stretch roll 19 and a guide roll 20. p

In structures heretofore available a series of rolls such as 19 or 20 would normally be located along the return run causing the wire to trace a zigzag path for tensioning and controlling the wire. At each roll the wire would make a sharp turn following the curvature of the roll and would have to drive the idler return roll.

In accordance with the present invention the return run of the wire is carried on a series of support members 21 and 22 having upper flat smooth support surfaces 21a and 22a are positioned to be in substantial alignment with the path of travel in the wire and supported horizontally without requiring it to bend or turn.

The support members may be formed of Formica or other hard surface smooth material which permits the sliding of the wire with very low uniform surface pressure. This construction substantially reduces the horsepower requirements to drive the Fourdrinier wire especially at the start-up. These structures also permit easier wire stringing for changing the wire. They also accommodate the wire to be cleaned easily. Another advantage is that the number of rolls in the Fourdrinier is substantially relifeand decrease the" "tendency to'ridge the Wire.

flectors is reduced and simplified flat surface deflectors may be substituted for rolls and doctors. Power consuming doctors are not needed on the Wire return rolls because of the elimination of the rolls.

4 face of the deflector engages the wire; A second rectangular hollow support channel 41 is secured within the first channel 40 by a pair of jack screws 42 and 43. A boss 44 is formed on the channel 41 and engages the inner surface of the channel 40 at the center thereof and adjacent the deflector '26. By adjusting the jack screws 42 and 43 the channel 40 may be bowed and this action will also bow the deflector 26. In order to enable adjustment of the wire support'surface 29 relative to the direction or path of wire travel along the return run, opposite end portions of the channel 40, disposed on either side In the arrangement illustrated in FIG. 2 the upper forming run f of the Fourdrinier Wire is substantially the same as with the arrangement of FIG. 1 and a series of flat support surfaces are employed. The wire travels down on its return run r and support members 23, 24 and 25 are employed each having an upper flat smooth surface and arranged substantially in a straight horizontal line for conveying the wire in a straight run. For tensioning machine providing surface support for the wire. The

support member may include separate means for individually, vertically adjusting a front and a rear of the support member 26 and thus its leading and trailing edges and 31, respectively, thereby enabling adjustment of a disposition of the support surface 29 relative to a direction of wire travel for aligning the surface in a parallel relationship thereto.

The upper surface 29 may be formed iii some installations with a special mirror-finished surface of refractory monolithic ceramic material such as a crystalline refractory metal oxide. A particularly satisfactory method of finishing the surface is in accordance With Bradstreet US. Pat. No. 2,904,449. The mirror-finished surface has a unique smoothness in the range of 200 to 300 microns. This arrangement has been found to be particularly advantageous in reducing Wear of the individual small filaments woven to comprise the forming wire.

As is well known, wire webs are not perfectly uniform as manufactured and therefore the stretch of the wire, under tension, will not be uniform across the width of the machine. Also, the support rolls deflect under their own weight and due to the Wire tension, giving a taped wire length at the centerline of the machine which will be one inch or more different than the Wire length at the' edge. This difference in Wire length makes it impossible to Y run the wire'with uniform tension across'the machine, and part of the wire will have to have a higher tension in order to maintain a minimum tension in the slack portions of the wire web. Also, rolls must be sized larger than necessary so as to keep deflections small thereby minimiZ-' ing the differences in taped lengths.

The flat top deflectors of the present invention can be used as a tool to obtain uniform taped length. By providingadjustable bowing means to the deflectors their surface may be changed from a downward deflection, due to their owri weight, to an upward deflection or bow. This willenable thedeflector to remove the slack and spread the wire uniformly and provide nearly uniform tension to th'ewir'e web across'th'emachine'. This feature will permit a reduction in the'necessary wire tension, increase'wire The" p'referred arrangement of mounting means i for bowin'ga support member deflector is shown in FIG. 4.

- and a guide 'IOll positioned on the return-run sid'e'be- 'A'fii's't rectangular hollowsupportchannel 40has the deflector 26 mounted thereon such that the upper flat surof the wire, are supported on adjustable supports as at 46 and 47. As indicated by arrows 48 and 49, each one of the supports 46 and 47 includes means for individually, vertically adjusting a position thereof relative to the path of the wire return run. Also, as indicated in FIGS. 1 and 2, a pair of the vertically adjustable supports 46, 46 or 47, 47 are disposed at each of a leading and trailing end portion ofthe'support members 21, 22, 23, 2 4,f'25 or 26 relative to an approach or a departure of the wire. Thus, by individually, vertically moving the two pairs of adjustable supports 46, 46 and 47, 47, the wire support surface 29 may be pivotally adjusted about a pair of axes respectively extending parallel to, and transversely of, the direction of wire travel for selectively positioning the surface in a, parallel relationship to the wire return run or path.

Thus it will be seen that we have provided an improved Fourdrinier wire structure which avoids disadvantages attendant with return rolls in units of the"'type-heretofore employed. The structure prevents wire ridgin'g and reduces wear and reduces driving power necessary extending the operating life of wires and thereby decreasing shutdown time and reducing wire cost and changing expense.-

The drawing and specification 'presenta detailed disclosure of the preferred embodiments of the'invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope-of the-principles'taught by the invention.

'I claim as my invention: I

1. In a papermaking machine, a Fourdr'inier section comprising a continuous looped 'Fourdrinier wire having a substantially horizontal web forming run and a return run, a breast roll Within the wire at the beginning of the web forming run supportingthe wire, a couch roll within the wire supporting the wire at the other end of the form'- ing run, wherein the improvement comprises:

a wire return support member beneath the wire along the return run having a stationary flat surface extending across the wire substantially parallel to its travel slidingly supporting the travelling wire over a substantial distance in the direction of wire travel Without bending the wire.

2. In a papermaking machine in accordance With claim 1, and further characterized by:

a return roll beneath the couch roll at the beginning of the return run,

and a turning roll at the end of the return run beneath the breast roll,

said return support member located between said return roll and said turning-roll. J

3. In a papermaking machinein accordance with claim 2, and further characterized by:

a 'tensioning roll positioned on the 'return run side be- .yond said return roll and-being vertically adjustable for increasing or decreasing the deflection above the wire path .in the return run to control the tension thereof,

, -yond-thetension roll and in advance. of-said. support member-and positioned to be substantially aligned with the surface thereoffor feeding the Wire levclly onto the surface.

4. In a papermaking machine in accordance with claim 1, and further characterized by:

at least three support members in substantial horizontal alignment so that the wire travels in the return run in a substantially straight line.

5. In a papermaking machine in accordance with claim 1, and further characterized by:

separate individual adjustment elements at the front and rear of the support member relative to the wire travel direction for vertically independently positioning the front and rear edge relative to the approach and departure of the wire.

6. In a papermaking machine in accordance with claim 1, and further characterized by:

means for adjusting a cross machining bow formed by said support member to provide a substantially uniform wire tension across said support member.

7. In a papermaking machine, a Fourdrinier section comprising a continuous looped Fourdrinier wire having a substantially horizontal web forming run and a return run; a breast roll within the wire at the beginning of the web forming run for supporting the wire; a couch roll Within the wire at an end of the forming run for supporting the wire; a return roll disposed beneath the couch roll at a beginning of the return run; and a turning roll at an end of the return run for directing the wire to the breast roll, wherein the improvement comprises return run support means disposed between said return roll and said turning roll and including:

at least one elongated support member disposed beneath the return run and extending transversely of a direction of travel of said wire and forming a stationary, horizontally extending, smooth support surface slidingly supporting said Fourdrinier wire along the return run for a substantial distance in a direction of wire travel without bending the wire,

means mounting said support member and engaging the same at opposite end portions thereof disposed on oppoosite sides of the wire and substantially midway between the end portion thereof, and

adjustment means adjusting said mounting means for deflecting said support member in a direction opposite a normal sag thereof,

6 whereby said support surface may be adjusted in a manner to transversely deflect said support member for providing substantially uniform tension to said wire across the Fourdrinier section. 5 8. In a papermaking machine, a Fourdrinier section comprising a continuous looped Fourdrinier wire having a substantially horizontal web forming run and a return run; a breast roll within the wire at the beginning of the web forming run for supporting the wire; a couch roll Within the wire at an end of the forming run for supporting the wire; a return roll disposed beneath the couch roll at a beginning of the return run; and a turning roll at an end of the return run for directing the wire to the breast roll, wherein the improvement comprises return run support means disposed between said return roll and said turning roll and including:

at least one elongated support member disposed beneath the return run and extending transversely of a direction of travel of said wire and forming a stationary, horizontally extending, smooth support surface slidingly supporting said Fourdrinier wire along the return run for a substantial distance in a direction of wire travel without bending the wire, adjustable support means mounting said support member and having portions individually supporting leading and trailing edge portions thereof, and adjustment means adjusting said support means for vertically, independently positioning the leading and trailing edge portions of said support member relative to an approach and a departure of said Fourdrinier wire.

S. LEON BASHORE, Primary Examiner F. FREI, Assistant Examiner US. Cl. X.R. 74-240; 162-199 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,556,937 Uatd January 19, 1971 DONALD B. DE NOYER Patent No.

Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 5, after "53511" insert '--assignor to Beloit Corpo Beloit, Wisconsin, a Corporation of Wisconsin.

Signed and sealed this 1 7th day of August 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

